FZD4 and Familial exudative vitreoretinopathy: Based on the identification of FEVR-like defects in IlkiECKO retinas, a cohort of genomic DNA samples from 208 exudative vitreoretinopathy patients, most of them sporadic cases with unknown genetic cause, were screened by Sanger sequencing for mutations in the 12 protein coding exons as well as flanking splice sites of the human ILK gene.